250 Tail Wag And Other Questions - Trex 250 - Ikon 2

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PancakeMSTR

Member
Hi,
So I recently got back into RC helis and I've been trying to setup a Trex 250 I had previously built back in like 2013 or something.

Mainly, I converted it to flybarless with the Ikon 2 FBL controller. I also bought a new transmitter (FrSky Horus X10S Express), and replaced the receiver with an X8R.

It's been a...journey... but things have actually gone reasonably well up until now. I've finally started flight testing the bird, and unfortunately I'm getting excessive tail wag for no obvious reason.

Here are things I've tried

  • Tightened tail rotor assembly so that it wasn't free to rotate about the tail boom (yeah, it was loose).
  • Replaced shot-to-shit 42 mm blades with brand new 37 mm blades.
  • Replaced the very sticky (would barely slide along the tail shaft, maybe the grease went bad?) micro heli tail rotor assembly with a nice metal align assembly that is nice and smooth (by my standards).
  • Played around with Tx gyro gain.
  • Spooled up Heli on my desk (yes, seriously) and watched for vibration in the tail. Did not see any, but was hard to tell through shitting my pants.
None of these have had any effect. I guess except for Tx gyro gain, but to remove the wag I have to set it so low the tail wanders.

Here are things I'm planning on trying
  • Set ESC (Align RCE-BL15X) BEC to 5.5V and 5.0V (I've read in various places that this has helped).
  • Replace the Align DS420 tail servo with a KST DS215MG (I've already done this, gonna flight test it this morning). I just flight tested the new servo and it actually seems to have helped quite a bit. There is still a small, high-frequency vibration in the tail that I'd like to fix (any ideas?), but it's definitely an improvement.
  • Play around with Ikon PID settings?
  • Other recommendations?

Lastly, tail wag aside, I have two questions about setting up the Ikon that I've been unable to answer:
  • I have my ESC (http://www.align.com.tw/ManuaLib/Heli/esc/G20310-RCE-BL15X_en.pdf) setup in Helicopter 2 Mode (Soft Start + Governor). My impression is that, in this mode, the ESC attempts to keep the motor spinning at a constant rate, and that's what you want for idle-up flight. So how should I configure the "Throttle out & Governor Setup" page on the Ikon? It's not really clear to me what throttle out is or the relationship between the Ikon and the align ESC, or in general what this page is supposed to be configuring. Can anyone help out?
  • My other question is about swashplate setup. You are supposed to set Cyclic deflection to 10 degrees, but I'm not sure where or under what conditions I'm supposed to set that angle? It's not well explained.
For reference, here's an imgur gallery of my transmitter settings (I'm using OpenTX) and my ikon settings:
Hope that is enough information! But obviously I'm happy to answer questions and try recommendations. Thanks for the help, and excited to be back into RC!
 
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Tony

Tony

Staff member
First thing that came to mind for me was tail gain. Make sure you are on the correct channel for tail gain, and set it to a positive number. If you have one that goes from -100 to +100, then set it to about 65 to start. If you have a tail gain that goes from 0-100, then set it at about 65.

One thing that I cannot see, and is commonly put on backwards is the tail blades. We have all done it, and it is not a fun experience. Also, make sure the tail blades are going counter clockwise when looking at the right side of the helicopter.

As for the governor in the Align ESC, that governor is horrible and should not be used. Just turn it off. Set the IU in the Tx throttle curve menu for IU1/IU2 for a flat curve, or a slight V curve if you would like. Anything below a 500 size helicopter (425mm blades) doesn't need a governor IMO. Just not enough blade to need constant rpm. Heavy 3D, then yes. Normal flying, no governor needed.

I would leave the PID settings alone in Ikon as it should be very stable stock out of the box. PID will be for very fine adjustments if you are getting oscillations at high speed, or when stopping the tail after a fast piro or something.
 
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PancakeMSTR

Member
Hi Thanks for the reply, been going off your youtube videos :)

Tony said:
First thing that came to mind for me was tail gain. Make sure you are on the correct channel for tail gain, and set it to a positive number. If you have one that goes from -100 to +100, then set it to about 65 to start. If you have a tail gain that goes from 0-100, then set it at about 65.
Click to expand...

When you say "make sure you are on the correct tail gain channel," what do you mean? Which channel should it be? I think I've got it set to channel 5 on my Tx, and when I adjust the gyro/gain channel on the Tx it adjusts the setting in the Ikon software. Is that as it should be?

And my gyro channel goes from +/-100, so should I set the gain in the Ikon software to 65%?

Tony said:
One thing that I cannot see, and is commonly put on backwards is the tail blades. We have all done it, and it is not a fun experience. Also, make sure the tail blades are going counter clockwise when looking at the right side of the helicopter.
Click to expand...

I've got the tails on like this:
Is that right? And I'll check that they spin the correct direction.

Tony said:
As for the governor in the Align ESC, that governor is horrible and should not be used. Just turn it off. Set the IU in the Tx throttle curve menu for IU1/IU2 for a flat curve, or a slight V curve if you would like. Anything below a 500 size helicopter (425mm blades) doesn't need a governor IMO. Just not enough blade to need constant rpm. Heavy 3D, then yes. Normal flying, no governor needed.
Click to expand...

I will do this and get back to you. Thanks for the heads-up. PS - can you suggest me a better ESC for my 250 or is it okay to stick with the Align with the governor off?

Tony said:
I would leave the PID settings alone in Ikon as it should be very stable stock out of the box. PID will be for very fine adjustments if you are getting oscillations at high speed, or when stopping the tail after a fast piro or something.
Click to expand...

Ok, I will leave this alone for the moment.
 
Tony

Tony

Staff member
The blades are on correctly, just make sure they are spinning counter clockwise in the aspect you are looking at in that video.

And it sounds like you have the tail gain set correctly, and I would set it to 45, but not in Ikon, but in your Tx (or use your Tx to move the slider to 45). This will need fine tuning.

Another thing to remember, these little 250's are, well, mine was called "Nightmare". I ended up just selling the helicopter before I got it to 100%. I would say, after replacing everything with Align parts (it was a clone), I got it to about 75%, maybe.

So check the tail blade direction and make sure the tail gain is good. Also, with the tail servo connected, make sure there is absolutely NO binding in the tail. Any binding will cause this issue.
 
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PancakeMSTR

Member
So I checked the tail rotor rotation direction and it's correct. I turned off the align ESC's governor and did a flight test and, tbh, it's flying pretty alright? There doesn't seem to be much tail wag anymore, though the tail is still a bit "twitchy," maybe a little more than I'd like it to be. Maybe that's just how it is, though.

I think I might replace that ESC though anyway. Can you talk about how the governor setup in the Ikon software is supposed to work? I'm confused by it.
 
Tony

Tony

Staff member
To use the governor in the Ikon, you will need an RPM signal wire from the ESC so that the Ikon knows how fast the head is spinning. The Align ESC's that small do not have this wire, and do not need it.

As for it getting better, I will bet dollars to doughnuts that the governor was kicking the tail around by "hunting" or "oscillating". This is one of the big issues with the Align Governors. Look at all of the Align kits now days, they ALL have HobbyWing ESC's in them, and for a really good reason.
 
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PancakeMSTR

Member
I bet you're right about the governor. Gonna try to pick up a new one in the next month or so.

Thanks for the help by the way. I've flown it a few times now and it really does seem to be behaving better.
 
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PancakeMSTR

Member
Hey Tony - or anyone else.

Even though I've been flying with the Horus and the X8R for not more than a month now, I'm kinda thinking about jumping ship. Specifically, to a radiomaster TX16S. The question is, should I stick with FrSky receivers, like the X8R, or should I switch to using different receivers?

Mostly I'm thinking about Spektrum's DSMX satellite system, and its compatibility with the Ikon 2. My main question is, do I need two satellites for the Ikon? Or can I make do with one? And is there anything else about spektrum satellites I should know about, or are they pretty straightforward?
 
Admiral

Admiral

Well-Known Member
With iKon & iKon2 I use one with below 500 size and two 500 and above, over several years have not had a problem.
 
Tony

Tony

Staff member
Correct, you will just plug the satellite directly into the Ikon, and within the software on the computer will be a bind button. Flip that on, power cycle the gyro and it will put the satellite receivers into bind mode.

I trust DSMX more than any other out there, but I have really only used Spektrum since I started.
 
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PancakeMSTR

Member
Hey again. I just got a Talon 25 ESC and am trying to figure out how to configure the throttle.

I've set the Talon to "Fixed Endpoints" mode, and the process I went through to set the endpoints was as follows:
  • Set throttle endpoints to +/- 75%
  • Turn on ESC with Throttle high
  • Move Throttle (+) endpoint up until I get a tone from the ESC (Acknowledging that it's recognized that value as max throttle. I assume). 97% for me.
  • Repeat process for throttle low, moving (-) endpoint down until I get a tone from the ESC . -97.4% for me.

Now here's where it starts to get confusing for me. For the Ikon, you are supposed to adjust the Tx throttle endpoints until the Throttle line reads 0% and 100% in the Ikon software transmitter setup page (Ikon Throttle Setup).
For me, this puts my throttle endpoints at -101.4% and 109.3%. Obviously, sizeably different from the endpoints I setup for the ESC.

So, how do you...deal with this? What's the correct way to setup up the ESC endpoints and the Ikon Throttle? Just confused about what you're supposed to do.
 
Tony

Tony

Staff member
The way I have always done it is I set my endpoints in the Ikon first, then I calibrate the ESC to match what my Tx is doing. On some ESC's, you actually need about 5 more clicks of down throttle to get it to arm, but only on some.
 
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PancakeMSTR

Member
Tony said:
The way I have always done it is I set my endpoints in the Ikon first, then I calibrate the ESC to match what my Tx is doing. On some ESC's, you actually need about 5 more clicks of down throttle to get it to arm, but only on some.
Click to expand...

Hey thanks Tony. Can you describe the exact process? I'm having weird issues here that I can't resolve and I want to make sure I'm doing things right. Thanks for the reply.
 
Tony

Tony

Staff member
My process is usually the following:

Setup the Ikon and Tx together to reach the values you stated above.

Remove all blades!

Raise the throttle on the Tx to 100% stick. Make sure throttle hold/cut is not activated

Plug in battery on helicopter, wait for I think 2 beeps (been a while), then immediately lower the throttle stick to 0

This has always setup my ESC's calibration perfectly. However, you are using a Castle ESC, and I cannot remember the procedure off the top of my head for Castle, but it can be more complicated than what I do for something like Hobbywing, which is my favorite ESC.
 
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